An example of conventional slide doors of this type is a slide door device for a vehicle as described in JP Utility Model Kokoku Publication No. 4-21703 (1992). FIGS. 14 to 16 show a slide door device disclosed in the JP UM Kokoku Publication. Thus, FIGS. 14 to 16 show an opened state of the slide door, a closed state of the slide door and a cross-section taken along a line 16--16 of FIG. 14, respectively.
In FIGS. 14 to 16, a mounting bracket 21 is mounted on a main vehicle body. Each of the link plates 23A, 23B of a parallel link 2 has its proximal end pivotally mounted on the mounting bracket 21 and has its distal end 231, 232 pivotally supported on a holding member 3. In FIG. 16, the link plate 23A is provided with a driving motor 26. The torque of the driving motor 26 is transmitted to a pinion 25 via a gear box 27 and a shaft 251.
In FIG. 16, a slide rail 1 is made up of a guide rail 12, an extension 14 and a main member 15, and is secured to a slide door S at the extension 14. In FIG. 14, a rack 13 having rack teeth 13a is provided within the guide rail 12, and has its rear end 131 bent at a larger angle into the inside of the main member 19.
The rack teeth 13a are engaged with a pinion 25. Rotation of the pinion 25 imparts a driving force to the slide rail 1 being in unison with the rack 13 and the slide door S, such that the slide door S is linearly movable in the fore-and-aft direction (left-and rightward direction in FIG. 14), basically along a straight section of the rack 13.
For closing the slide door S, it is moved forwardly (towards the right in FIG. 14). When a curved rear end 131 of the rack 13 reaches the pinion 25, forward movement of the slide door S ceases. The curved rear end 131 then travels along its curve by operation of a pinion 25, while the link plate 23A is rotated about a distal end 231 forming the proximal end of the link plate 23A, as a result of which the parallel link 2 in its entirety is swung towards the inner side of the vehicle, with the slide door S being moved towards the inner side in a direction at right angles to a pivotal (link) shaft of the main member (as seen in FIG. 14) and closed. FIG. 15 shows such closed state of the slide door S.